Machine for boring oppositely tapering coaxial holes in spaced parallel wall parts



May\28, 1957 N mc 2,793,545

MACHINE FOR BORING OPPOSITELY TAPERING COAXIAL HOLES IN SPACED PARALLELWALL PARTS FiledApril 15, 1954 11 Sheets-Sheet 1 INVENTOR.

glmofeMBepgdicf,

WW, ATTORNEY.

y 28, 1957 E M BENEDICT 2,793,545

MACHINE FOR BORING 'oPPosITELY TAPERING coAxlAL HOLES IN SPACED PARALLELWALL. PARTS 11 Sheets-Sheet 2 Filed April 15, 1954 27 INVENTOR.

v 12 Elmore/1B 0dr), 26wrzmm 133 134131 ATTORNEY.

May 28, 1957 E Emc 2,793,545

M. BEN T MACHINE FOR BORING OPPOSITELY TAPERING COAXIAL HOLES IN SPACBDPARALLEL WALL PARTS i Filed April '15, 1954 L 11 Sheets-Sheet 3 IN V ENTOR.

1 51 50 1 ElmoreMBezzedicf,

ATTORNEY.

I May 8. 1957 E. M. BENEDICT 2,793

' MACHINE FOR BORING POSITELY TAPERING COAXIAL HOLES m SPAG PARALLELWALL. PA Filed April 15, 1954 RTS l1 Sheets-Sheet 4 IN VEN TOR.

ATTORNEY.

May ZS, BE'NEDlCT MACHINE FOR BGRI OPPOSITELY TAPERING COAXIAL HOLES INSPACED PARALLEL WALL PARTS Filed April 15, 1954 ll Sheets-Sheet 5ATTORNEY.

y 8, 1957 E. M. BENED T 2,793,545

ORING o MACHINE FOR B OSITE TAP ING COAXIAL HOLES IN SPACE ARALLEL WAPARTS Filed April 15, 1954 ll Sheets-Sheet 6 I INVENTUR. Elmore/V.Benedlcf, BY o usir'w.

ATTORNEY.

y 28, 1957 E. M. BENEDICT 2,793,545

MACHINE FOR BORING QPPOSITELY TAPERING COAXIAL HOLES IN SPACED PARALLELWALL PARTS I Filed April 15, 1954 ll Sheefcs-Sheet 7 I H i r E3 E 5; VglmoreMfiinedicf,

ATTORNEY May 28, '1957 E. M. BENEDICT 2,793,545

ORING OPPOSITELY TAPERING COAXIAL V HOLES IN SPACED PARALLEL WALL PARTSFiled April 15, 1954 11 Sheets-Sheet s MACHINE FOR B INVENTOR.

ElmoreM media, BY I ATTORNEY.

Mayl28, 1957 E .BE NEDICT,,. 2,793,545 I MACHINE FOR BORI OPPOSITELYTAPERING COAXIAL HOLES IN SPACED PARALLEL WALL PARTS Filed April 15,1954 11 sheets-sheet @9 166\ v 1&1 164 I INVENTOR.

Elmore/Hamid .121

K ATTORNEY 11 Sheets-Sheet 10 E. M. BENEDICT PPOSITELY TAPERING COAXIALD PARALLEL WALL. PARTS May 28, 1957 MACHINE FOR BORING O HOLES IN SPACEFiled April 15, 1954 R .E M M J m m m MN r v E aa Mk Hmm HQ pmv. Q Q Efi mm B E B. m m v N J @V/L I m k NEE 3E Lwmsm E l, E 7. .Q

May 28. 1957 E. M. BENEDICT 2,793,545

MACHINE FOR BORING OPPOSITELY TAPERING COAXIAL HOLES IN SPACED PARALLELWALL PARTS Filed April 15, 1954- 11 Sheets-Sheet 11 it go?" UnitedStates Patent 17 Claims. (Cl. 77-3) This invention relates to a machinefor boring oppositely tapering coaxial holes in spaced parallel wallparts.

In prior practice oppositely tapering holes in parallel wall parts havebeen formed in separate and independent operations.

The principal object of the invention, as a matter of substantialeconomy of manufacturing operation, is to provide a machine in which theboring operation and the subsequent release of the work from the boringmedium.

general character and appropriately different specific design when,according to choice, the directions of the tapers cut by the machine areto be reversed or when the operation of the machine is to be limited tothe boring of the taper only in the anterior wall.

A further object is to provide a machine of the character stated inwhich all operative phases, including the opera tions of the boringbars, positional adjustments of the various parts, and the operation ofthe mechanism for controlling the operation of the motors are effectedby power.

The invention comprehends a machine having the above essentialcharacteristics and otherwise characterized by novel features ofstructure and combination whereby the above objects are served.

In the example selected for illustration the structural element in whichtapers are to be bored is a water filled unit of a sectional boiler butit will be understood that machines embodying the invention may be usedfor boring oppositely tapering coaxial holes in spaced parallel walls ofelements of different design, that is to say elements designed as partsof various structural assemblies 1 for different specific uses, forexample, radiator units.

are accomplished serially in a sequence of steps involving relativemovements of the various parts in what is essentially a single operationfor tapering both of the holes.

The machine, among other essential features, includes a boring barhaving a driving element and a boring head having diametricallyoppositely located cutters, the cutters as oppositely located being forboring the tapers in the openings of the respective walls. In carryingout the above stated principal object the invention fundamentallyprovides for rectilinear posi'tionally adjustable relative movements ofthe driving element and the work and movements of the boring headrelatively both to the driving element and the work, certain of whichmovements involvethe feeding of the cutters into and through the workand all of which movements are carried out in a cycle of operationinvolving a series of coordinated steps and an appropriate selection ofthe relation of the cutters for operation in a predetermined sequence.

As other essential features the driving element is arranged along aninclined axis and is rotatable abouta major'axis, preferably horizontal,and the boring head itself has an axis which extends in the samedirection as the major axis and is carried by a part slidably and adWith these justably movable along the inclined axis. characteristics inmind further objects are to provide a machine having the capacity forappropriate selection of the directions and extents of the relativemovements of the driving element, the boring head and the work, thedurations of their periods of rest and the relative arrange- Thedrawings illustrate an embodiment of the invention which, as nowconsidered, is preferred. In the drawings: Figure l is a front elevationof a machine in accordance with the invention, with the work unit, i.e., the structural element, shown as positioned on its carrier.

Figure 2 is a side elevation of the machine.

Figure 3 is a vertical transverse sectional view on the line 3--3 ofFigure 2. 1

Figure 4 is a vertical transverse sectional view on the line 4-4 ofFigure 2.

Figure 5 is a vertical sectional view on the line 5--5 of Figure 1.

Figure 6 is a horizontal sectional view on the line I 6-6 of Figure 2.

Figure 7 is a perspective view of one of two similar devices forclamping engagement with the upper portion of the structural elementupon which the machine operates.

Figure 8 is a detail horizontal sectional view on the line 88 of Figure3.

Figure 9 is a perspective View of one of two similarline 10-10 of Figure3.

ment of the cutters, whereby, according to choice, the

tapers may be bored with their minimum diameters in either mean orextreme relation and in either instance their degree of angularity maybe varied from the maximum permissive degree.

A further object is to provide a machine of the character stated inwhich several pairs of alining oppositely tapering holes may besimultaneously bored.

As other essential elements the machine includes separate motors foreffecting the steps of relative movement of the boring head and the workand a mechanism for controlling the operation of the motors in respectto the directions, extents and sequences of such movements. With thesecharacteristics in mind a further object is to provide a mechanism forcontrolling the operation of the motors which has a governing elementspecifically designed for effecting the particular directions, extentsand sequences of the steps of movement of the driving element, theboring head and the work which element may be re- Figure 11 is ahorizontal sectional view of one of two similarly constructed and actingvalves for controlling respectively the movements of the carriage forthe struc tural element and the movements of the slidably mountedspindles of the boring bars, the valve shown in this figure being thevalve which controls the movements of the carriage.

Figure 12 is an elevation of the governing element which is. shown intheform of a rotatable electrical I contact-carrying disk.

placedby a similarly functioning element of the same Figures 13 and 14are complementary graphs as indi- :cated by the bracket showing thesequence of the steps of movement of the boring head and the work whenthe Figure 15 is a central horizontal sectional view on the line 15-15of Figure 2 of one of the boring bars and the associated parts, theboring head and the work being diagrammatically shown in their relativepositions prior to the. commencement of the boring operations. It willbe understood that the several boring bars are of similar construction.Figures 16 to 20 are a series of diagrammatic views of similar characterin the same horizontal plane as Figure 15 I which, like the diagrammaticshowing'of Figure ISQaS- 5 sume the boring of tapers in the two walls inwhich the" minimum diameters'are in mean relation: and thefriiaximumdiameters'are' in extreme" relation. These fi gtir'esf show the relativepositions of the "boring head' and' 'the, work'in the different steps ofoperation. In'theseftig' ir'es', the'work is shown "in'sectiontakenin'the same plane in i which his 'showni'n'Figure 15'. Figure 16"showsthemelative positions of thc b oring headandthe 'work when thework been advancedio a pos'itionin which'the outerfonanterioi" face ofits 541 terior'w'allis substantially coincident'with'th boring' headandthe opening"infthegjante I v, opening being formed in the'finoldi ngioperationftfi be: cut-with-ataper'-is presented mm ering;

Figure- 17 shjows 'thei"elative "positions" of t he horing headahdthe-workwheii'thefwork been shif 'd'fr the position show'ninFigure""16"t:o"a position the 1inne'r 'on anferior face of theposteriorfwall is' sub'; stantially-coincident "withthetace of 'thefborihea' andtheopening'iri'the posterior wall (the openin m formedintheinoldingoper ion) is 'presente to cutterslv: "1 ml? i v t Figure 18shows the boring head and the work when the work has been shiftedfr'omthe position shownin j Figure 16 to a position-in which the-posterior orouter '30 face'of the posterior-wall is located'at a-suitablejdis'ta inadvance ofth'e 'l-eadingmractive edges of the cutters in preparation forthe-movement of the boring head through an initial retractile step,thereby to'pullj all of the cutters through the'tapered opening which'hasbee n cut in the posteriorwall.

Figure 19 shows the'work in the same position in which it is shown inFigure 18 but with the boring head at the. completion of its first stepof'retrac tilemovemeht.

Figure 20 shows the work as shifted from" its position shownin Figure 19back to its original position which is shown in Figure'lS. This movementof the work enables the' bon'ng head to be moved back'toits originalposition as shown in broken lines. Figure 21 is 'adiagram showing theconcentric rotation of the axial center of the spindlewhich carries the"boring head about the fixed'axisof" rotation of the gbor- Figure 22 isa diagram showing the relation of the central axis of the spindle whichcarries the boring head, the g fixed central axis of *rotatibnof theboring bar and the central axis of the boring head when the'work and theboringheadhave been brought into the relation shown in Figure 16. i isFigure 23 is a diagram showing the manner in which the central axis ofthe" boring head'moves' away from the fixed central axis of rota-tionofthe boring barwhen the boring headis advanced in 'the direction of theaxis ofits spindle in the course of the cutting operations.

Figure 24 (Sheet 4') is ahorizontal section on theline 2424'ofFigu re-5,showing details of the fluid'motor" for effecting the movements of thecarrier'for'the"struc-" tun-a1 unit. Figure 25 is a horizontal sectionalview showing details of themanually operated valve for controlling" theop eration of the work clamping means, the valve body'bein'g showninelevation. 1 i Figure 26 is a vertical sectional view on the line 2626of Figure 25 showing the path of flow of the operating fluid to effectthe clamping action. I Figure-27 is'a vertical sectional view on theline 2 7--2 7 of Figure 25 showing the valve body in the same positionand the path of return flow of the operating fluid. Figure 28 isa wiringdiagram showing the solenoids for the operationot the valve bodies ofthefiuid mast-W illustrated in Figures 5 and 24 and the motor driven Icontact carrier which controls" the energiziation and deenergization ofthe solenoids.

Figures 29 and 30 are complementary graphs as indicated by the bracketshowing the sequences of steps of movement of the boring head and thework when the tapers to be cut have their minimum diameters in extremerelation and their maximum diameter-s in mean r el a tio n,, gu 2 ng a ea-p b ihebperl xe mevem ntsot, the Boring head and Figure 30 a graph ofthe operative.

being shown in section in the same plane in which it is shown in Figures15 to 29.

Figure 31 shows the boring head and the;work in their,

relative positions prior to the commencement of theboring operations andafter their completion Figure 32 shows the relatiye positiolisv,of theboring. d d e-w rk when th rw rkhas been a vanced ,to a position inwhieh'the outer or anterior face of the anterior wa t is substantiallycoincident withthe end face.

of the boring head and the opening in the anterior. wall is Pr llt d 1 t1 T-.

Figure 3 3 show s the relative positions, of the boring head and thework at thecompletionof the. cutting of the taper the opening in theanterior wall.

Figure 34 shQW, ,,th r la ive. positions of the boring". head and thework immediately priortothe cuttingof the theposterior wall.Thesepositionsmaybe called "COIlQlltlPIlil'lgi positions in that,theyiare. in preparation,v

taper for the cutting of thetaper in, the: posteriorrwall. a

Figure 35 shows therelative. positions. of the boring I headandtheworkwhenithe.. .work. has beenshiftednto present the anterior face, oftheposterior wall to the-boring h d I Figure 36 shows the relativepositions of the-work and the boring head Whenthe taper has been cut inthe opening in the posterior wall,

Figure 37 sho'ws the .relative positions of the boring head and the,work when the boring head has'been com-. pletely withdrawn from theworkand both the boring head, and the fwork have been restored to theiroriginal 7 positions.

Figure 38 .is a schematic side elevation showing a ma- I chine ofmodified construction in which the work unit is zontal plane as Figures15 and "16 through 20' and are arranged conjointly .to' constituteagraph (as indicated by the bracketf'showing the relatiyepositionjs ofthe work and the: boring head in correspondence to the positionsshown'individually in" Figure'sld'to 20' respectively.

As an example of work selected for illustration the drawings show a"section orunit U offa sectional boiler of a wellk'nowngeneralty'pe','the details here pertinent being sufficiently shown inFigures 1,3, 5' and 15 through 20. In the assembled "boiler units ot theconstruction shown in the drawings are mounted in superposed rela-,

tion and'in'each instance'includeia horizontal marginal water chamber C(Figure 5'). Thewaterchambers of adjoining units a'r'ej'in opencommunication with one another'at'any desired numher of points, In theexam-v ple shown the ":oinrniinication,is at three symmetrically spacedpoints fFoithe purpose ofes't'ablishing such communicatiofieach unit isfo'rmed withhoriiontal extensions "(Figure" 1')f which project QradiaIIy Loutward and are 'rcularly pan/ed; These hayeiparallel walls as 'bestshowninFigure's lS'thro'ugh 20', one wall, designated 5 A, beinganterior and the other, designated P, being posterior. In the molding ofthe units openings are formed in the walls A and P and the machine ofthe invention 'bores tapers in these openings. In the assembly of theunits to form the boiler the tapering openings are in alinement toprovide continuous vertical water flow passages. The adjoining units areconnected and their meeting faces sealed by thimbles of well knownconstruction which is standard practice are fittedclosely in thetapering walls of adjoining extensions K and have external surfaceswhich conform in taper to the tapers of the openings of the adjoiningextensions. Since these thimbles are well known and form no part of theinvention their illustration is deemed unnecessary.

In the example shown the openings 0 of one series are of substantiallygreater diameter than the openings of the other two series. The openingsof greater diameter are provided in order that the water passage whichthey delimit may serve also as a casing for awater heating coilconnected to the hot water supply line. As shown in Figure 3 the unit ispositioned for the drilling of the tapers with the extensions K in whichthe openings of greater diameter are formed centrally located at the topand the extensions K in which the openings of less diameter are formedlocated at or near the lower side.

The machine includes three boring bars (using the term bar in the senseof an organization), one for each pair of alining openings. The boringbars are of structurally similar character and include boring headswhich have the same movements similarly and sirnultaneously performed.The illustration in detail of one boring bar will therefore serve forall, the bar selected for illustration in Figure 15 being shown inrelation to an extension K in which openings of less diameter areformed.

Each boring bar includes a driving element for the boring head. In thepreferred embodiment (Figures 1 through 37) the driving element has afixed mounting and the work has a sequence of rectilinear movementsrelatively to the driving element. Within its purview the inventioncomprehends relative movements of the Work and the driving element bymovements of the driving element relatively to' the Work as fixedlymounted (Figure 38). In either case the boring head has move ments alongan inclined path relatively both to the driving element and the work.

The frame of the machine (Figures 2, 4 and includes a horizontal base 1which carries fixed front and rear upright pedestals 2. and 3 positionedin parallel transverse planes.

The boring bars are indicated generally at 4 and as shown in Figure in.each instance have a driving element 5 in the form of a hollow shaftinclined along a central axis W. The shaft 5 carries front and rear endjournals 6 and 7 respectively concentric with a major axis X which ispreferably horizontal and is at all times coincident with the commonaxis X0 of the alining openings O. The angle of the axes W and Xdetermines the maximum permissive degree of the taper. The shaft 5drives, and preferably encloses, a spindle 9 inclined along the axis Wand mounted for longitudinal sliding movement relatively to the shaft 5.The axes W and X meet or intersect at a fixed point Z appropriatelylocated behind the rear end face of the spindle 9. At its rear end, i.e., its end beyond the point Z, the spindle carries in driving relationa boring head 10 located beyond the rear journal 7 and in projectingrelation to the shaft 5, thehead 10, having a central horizontal axis Ywhich, prior to the boring operation, is coincident with the major axis(3 of the journals 6 and 7.

The driving connection between the boring head it) and the spindle 9 isof detachable nature, thereby to enable the angular adjustment of thecutters carried by the boring head relatively to the spindle 9 or thesubstitution of a boring head of appropriate diameter for the particularopenings, in which tapers are to be bored. The inner end face of theboring head 10 is preferably in a vertical plane, that is to say a planenormal to the axis Y, and abuts the rear end face of the spindle 9. Thedriving connection of the head 10 is in the well known form of anextension 11 of annular cross section and reduced diameter, suchextension being coaxial with the head 10 and having the usual slightdegree of taper. The extension 11 fits comformably in a recess 12 opento the rear end face of the spindle 9, the annular wall of the recesshaving a taper corresponding to the taper of the extension 11. The head10 is maintained in driven relation to the spindle 9 by a screw 13fitted in a central axially extending opening in the head with its shankprojecting beyond the extension 11, the projecting portion of the screwshank being engaged in a threaded recess 14 in countersunk and coaxialrelation to the recess 12. When the screw 13 is tightened the extension11 is drawn into tight wedging contact with the wall of the recess 12.When the screw 13 is backed off the boring head may be angularlyadjusted relatively to the spindle 9, thereby to vary the extent of theradial movement of the cutters relatively to the axes X and X0consequent to the movement of the spindle 9 in the hole boring operation. It will be noted that the axes W and Y lie in a diametrical plane(which is assumed as the plane of the section of Figure 15) and that theaxis Y is shiftable in this plane relatively to the axes X and X0 asthespindle 9 is advanced in the hole boring operation. If, prior to thestart of the operation, the cutters be positioned with their leadingedges in this plane (as shown in the drawings) the cutters will have themaximum extent of radial movement relatively to the axes X and X0 as thespindle 9 is advanced. However if the cutters by angular positionaladjustment of the boring head 10 be originally positioned with theirleading edges in a diametrical plane at an angle to the plane whichincludes the axes W and Y the extent of the radial movement of thecutters relatively to the axes X and X0 as the spindle 9 is advancedwillbe decreased in proportion to the increase of angularity of theintersecting planes with the results (1) that a positional adjustment ofthe boring head 10 through an angle of from the position assumed in thedrawing will reduce the extent of the radial movement of the cuttersrelatively to the axes X and X0 consequent to the advancing movement ofthe spindle from the maximum extent assumed in the drawings to zero, and(2) an angular positional adjustment of the boring head 10 beyond anangle of 90 and up to an angle of will reverse the direction of theradial movement of the cutters relatively to the axes X and X0 and theextent of such reversed radial movement will be progressively increasedto a maximum at 180.

The shaft 5 carries in fixed relation suitably spaced internal sleeves 8which serve with a minimum of frictional contact for guiding the spindle9 in its slidable movements. The shafts 5 are mounted in the pedestals 2and 3 by means of ball bearings 17, the inner bearing rings beingmounted fast on the journals 6 and 7. The shafts 5 of the two lowerboring bars are directly mounted in bearing blocks 15 and 16 carried bythe respective pedestals 2 and 3. Adjacent the pedestal 3 each shaft 5is formed with an inwardly extending cylindrical face 18 concentric tothe axis X. Eachshaft 5 has an extension 19 beyond the journal 6 andconcentric to the axis X to which a driving pulley 20 is connected byscrews 21, the pulley being directly mounted upon an adapter clampedbetween it and the end face of the extension 19.

The spindle 9 is driven from the shaft 5 by means of a suitable key 23mounted for longitudinal movement in either direction relatively to theshaft 5, the key according to its direction of longitudinal movementeffecting the advancing or retractile movements of the spindle. The key23 has a secure fit in a ,diametrical opening 25 formed inthe-spindle9.To insure this the key is made intwo parts 25 and 26' having cooperatingwedge faces. These faces are formed to delimit an opening for adiametrically'arrange'dscrew 27, a part 28 of the opening wholly-withinthe'key part ZS 'being threaded for cooperation-with the screw. Thefunction of the screw 27 is relatively toexpand'the key parts intostrong frictional contact with the-wall of theopening 24. T he'endportions of the key parts 25 and '26 project suitably beyondthe spindie9'and are located in longitudinal slots 29 corresponding in width to thediameter of the key and formed in the shaft between its cylindricalfaces, thereby to couple the spindle9in'driven and slidablyrnountedrelation'to the shaft 5. The key 23 is accordingly movable in "eitherdirection, lengthwise of the shaft, in the slots 29,-its movement beingeffected by 'acollar 3t) rotatable with the shaft '5 'and'slidablymounted upon its face 18. The'collar' 30 is provided "with diametricallyopposite openings 31 and 32, the opening 31'giving'access to the head ofthe screw '27 and the opening 32 accommodating with a suitableloose butdriving fit that portion of the key part '25'which projects beyond theface 18. The movement 'of the collar 30 along the face 18 istransm'ittedby the key 23 to the spindle 9.

The boring head carries radially projecting cutters arranged indiametrically opposite relation and preferably provided inpairs, thecutters of 'a' pair being in longitudinal'alinement and being roughingand finishing cutters respectively. The cutters of one pair form thetaper in the opening of the wall A and the cutters of the'second pairform the taper in the opening of the wall P. According to the angularpositional adjustment of the boring head "10' relatively to the spindle9 the opposite tapers maybe cut in either direction and in variousdegrees of angularity less than'rnaximum.

Figures through assume that the tapers will be cut with-their permissivemaximum 'angularity and with their minimum diameters in mean relation.The cutters are arranged in first and second pairs, these terms beingused with reference to the sequence in'which the pairs of cuttersoperate. In Figures 15 through 20 the first cutters 33 and 34 cut thetaper of the hole in wall A and the second cutters 35 and 36 cut thetaper of the hole in the wall P. The finishing cutter of each pairfollows "the roughing cutter and projects a few thousandths of'a'n inch,e. g. .015, beyond it. In the example assumed by Figures 15 through 20the cutters 33 and 34 have a slightly greater projection from theperiphery of the head v10 than the cutters 35 and 36, i. e., of theorder of .019 inch. the cutters 33 and 34 is' provided for the reasonthat while they are cutting the taper of the hole in the wall A thecutters 35 and 36 must move through the hole without contact with itswall.

In'the example shown in Figures 15 through 20, as the boring head '10 isadvanced the cutters 33 and 34 approach'the major axis X and the cutters35 and 36 move away from it. Since the cutters 33 and 34 have a greaterdegree of projection from the boring head than the cutters 35"and 36they are operative to cut the taper in the opening of the anterior-wall.These figures assume that in any position of the boring head 10consequent to the movement of the spindle 9 along its axis W the pairsof cutters are respectively at their perrnissible maximum and minimumdistances radially from the axis X. By the angular adjustment of theboring head in either direction about its axis Y through an angle of 90from the positionassumed in Figures 15 through 20 the extent of theradial movement of the cutters relatively to the axes X and X0 as'theboring head is advanced may be progressively'varied. In this manner theangularity of the tapers i'n'the'two walls maybe predeterminatelydecreascdfrorn the permissive maximum degree. With reference to theposition of the boring head shown in Figures 15 through 20 i ts' angularadjustmentthrough an angle of 90 pro- This greater degree of projectionof gressively reduces the "extent .of radial movement ofthe cutters331and 34 relatively to the.-axes.X and X0 asthe boring head isadvanced, whereby theangleof thetaper ofzthe opening in thewall vA maybe=progressively reduced frommaximum {to zero .at 90.- When the. angularadjustment .of the'boring head 10. about its axis-Y ;is to becontinuedbeyondl90 from the position assumed in Figures 15 through .520and up :to'180"- the taper is cut in the wall A by the cutters 35 and 36,and in the wall P by the cutters 33 .and 34. :In such instancesthecutters 35 and 36 are positioned toproject-radiallythrough anappropriately greaterzdistancefrom the periphery of the boringheadthanthe cutters 33 and 34 and the directions of the tapers arereversed from the directions-assumed in Figures 15 through 20. a

A separate electric. motor is preferably provided for each shaft 5. Themotor 37 for the upper boring bar (Figures 1,2 and 5 beingconsidered)-is mounted on a bracket 38 secured by boltsto the flat upper edge facesof the pedestals Zand 3 and .its shaft carries a pulley '39 connected byabelt or belts 40-to the pulley 20-of the shaft 5 of the upper boringbar. 'Thetmotors 41 for the shafts 5 of the two lower boring bars aremountedton laterally projecting brackets 42,. each formed with anattachment plate43-securedbyboltsto the flat inclined side edge faces.of the pedestal 2, the shafts of the motors 41 being similarly beltgeared .to the respective pulleys 20 of theshafts 5 of the two lowerboring bars.

The work U is :securedin upright position beyond the boring bars in ,aplane normal to theaxis X. The supports for the workunit .and the boringbars .may be re garded as companion elements having rectilinear relativemovements, one element being fixed and the other being movable. 'In thepreferred embodiment the unit U is mounted upon a carrier 44 (Figures 1,2, 3 and 5) which consists of a base 45 and a frame .46 mounted upon itin upright relation in a transverse plane. Theframe base 1 is providedalong its sides with projecting flanges .47. The carrierbase 45 hasdepending side walls 48 to the lower faces of which securing strips 49are attached, these engaging under the flanges 47 and preventing anyupward or canting displacement of the carrier. The frame base 1 ispreferably formed in its upper face with a longitudinal way 50 havingsides which flare upward and the carrier base 45 is fashioned withprojections 51 on its under face which are inclined conformably to andbear against the sides of the way 54 The frame 46 conforms in generaloutline'to the work and has an upward extension 52 to accommodate workclamping means. This preferably includes a vertically movable cylinder53 hydraulically operated in relation to a fixed piston 54 provided atthe lower end of a stem 55. The piston carrying stem 55 projects throughthe upper head of the cylinder, is pendent from the bow or cross pieceat the upper end of the extension 52, and has passages for the flow ofthe operating fluid into and from the .spaces at each side of thepiston. The cylinder 53 is formed with vertical diametrically opposedexternal flanges .56 which bear against the vertical side pieces of theextension 52 and carry work engaging elements 57; These are shown indetail in Figure 7 and are secured by screws 58 to the lower ends of theflanges 56. The elements 57 have their inner faces formed with recesses59 which accommodate and center the work unit extension K. Other workengaging elements 60 are arranged on the carrier base 45 and are securedby screws 61 to the side bars of the frame 46. The elements 66 engagethe two lower extensions K of the work unit U and have theirinner facesformed with recesses 62 which similarly accommodate and center theseextensions. It will be apparent that when the cylinder 53 is moved toits lower position and held in such position under the pressure of theoper ating fluid the elements 57 and 60 will engage the annular walls ofthe extensions K and will cooperate in securelyholding the work unitwithin the frame of the carrier a-positionunwhich-its openings 0 are,and

at all times remain, concentric with extensions of the axes X. Theflowof the operating fluid to and from the cylinder 53 is controlled by amanually operated valve 63 (Figure 2).

The carrier44 is moved rectilinearly in either direction and throughsteps of appropriate length by a fluid motor 64 (Figures and 6) having afixed piston 65 mounted on a stem 66 and a movable cylinder 67. The stem66 is secured to a lug 68 mounted on the frame base 1 and the cylinder67 carries a centrally located axially projecting post 69 tapped into anopening in the inner edge face of the carrier base 45. The pistoncarrying stem 66 is similar in construction to the stem of the workclamping means 55. The cylinder 67 is preferably slidably mounted in anopening in the pedestal 3, specifically in a block 74) provided on theframe base and located within an opening 71 formed in the pedestal 3 toreduce weight. The slidable movements of the spindles 9 are effected bya vertical spider 72 mounted in a transverse plane (Figures 4 and 5). Inthe example shown the spider 72 is of generally inverted Y shape and isformed with three arms 73, each serving for the operation of one of thespindles. The spider 72 is prevented from turning about a hori- With thework remaining in position D the boring head zontal axis by a guide rod74 extending between the pedestals 2 and 3 and passing through anopening in the upper arm 73 of the spider. The spider 72 directlyeffects the movements of the collars 30. For this purpose each collar isformed with a circumscribing annular flange 75 in a plane normal to theaxis X and each arm 73 carries at its outer end a pair of antifrictionrollers 76 tracking upon opposite side faces of the flange of thecorresponding collar. The spider 72 is operated by a fluid motor 77which has a fixed piston 78 and a movable cylinder 79. The pedestal 2carries a horizontally projecting bracket 80 and the stem 81 of thepiston 78, which is similar in construction to the stem 66, is fixed to,and projects horizontally from the end wall of the bracket 80. Thespider 72 has a central opening in which the cylinder 79 fits, thespider being clamped in position between an annular flange 82 on thecylinder and a collar 83 threaded upon the end of the cylinder. Thepedestal 3 serves as a support and guide for the cylinder 79 and isformed with an opening 84 within which the cylinder 79 has its slidingmovement. The bracket 80 is conveniently in cylindrical form, isattached by a screw 85 to the pedestal 2, and has an opening 86 whichgives access to the nut 87 by which the piston stem 81 is secured.

In the preferred embodiment shown the work U has four vertical planarpositions indicated respectively in Figures 15, 16, 17 and 18 and alsorespectively in Figures 43, 39, and 41 as B, C, D and E and the boringhead has four positions indicated respectively in Figures 15, 17, 18 and19 as F, G, H and I and also respectively in Figures 43, 40, 41 and 42.I

Figure 15 shows the work and the boring head in relatively inactivepositions. In this figure the work unit U is in position B and issuitably spaced back of the boring head 10 which is in position F.

The first step in the operation of the machine is shown in Figures 16and 39. In this step, while the boring head remains stationary inposition F, the work is advanced from position B (Figure 15) to positionC in which the anterior face of the anterior wall A is in a planesubstantially coincident with the vertical plane of the leading oractive edge of the cutter 33 and the wall of the anterior opening 0 isoperatively presented to the cutters 33 and 34. With thework remainingin position C the boring head is advanced in a direction opposite tothat of the advancing movement of the work to position G (indicated inbroken lines) whereby the cutters 33 and 34 are fed through the anterioropening 0 and cut the required taper of its wall. The tapering cut ofthe anterior opening 0 is sufiiciently shown in Figure 17 by resort tothe expedient of dot and dash extension lines.

The second step of movement of the work is shown in is advanced in adirection opposite to that of the advancing movement of the work toposition H (indicated in broken lines) whereby the cutters 35 and 36 arefed through the posterior opening 0 and cut the required taper of itswall. The tapering cut of the posterior opening 0 is shown in Figure 17by resort to the expedient of dot and dash extension lines.

After the tapers have been cut in the anterior and posterior openings asabove described, the work is moved to positions which enable the returnof the boring head 10 to its initial or inactive position shown inFigure 15. These movements of the work and of the boring head are shownin the order of their succession :in Figures 18, 19 and 20 (in which thefinal position of the boring head is shown in broken lines).

With the boring head remaining in its position H as shown in Figures 18and 41 the work is then advanced in the same direction as before throughits third step of movement (shown in broken lines in Figure 41) toposition E shown in full lines in Figures 19 and 42. This position ofthe work permits the boring head to be moved in the direction oppositeto that of its previous movements, i. e., retractile direction through afirst step in its Withdrawal from the Work. This step is shown inFigures l9 and 42 and involves the movement of the boring head toposition I while the Work remains in position E. The advance of the workto position E insures that the cutters may be withdrawn from theposterior opening 0 without contact with its wall. In position I of theboring head the cutters 36 and 34 have been completely withdrawn fromthe posterior opening 0 while the cutters 35 and 33 remain in suchopening but without contact with its Wall.

With the boring head remaining in position I the next step in itswithdrawal from the work is the retractile movement of the work (asshown in broken lines in Figure 42) from position E back to its initialposition B. These relative positions of the work unit and the boringhead are shown in Figures 20 and 43. At this stage the cutters 35 and 33are located behind the anterior wall A of the work and the cutters 36and 34 are located within the anterior opening 0 but without contactwith its wall.

After the work has been returned to its initial position B and while itremains in such position the boring head is moved through the second andfinal step in its withdrawal. In this step the boring head is moved fromposition I back to its initial or inactive position F (indicated inbroken lines in Figures 20 and 43), the cutters 35 and 33 beingwithdrawn from the anterior opening 0 without contact with its wall. Thework and the boring head at such time are in the relative positionsshown in Figure 15 At this stage the work is removed from the carrier 44and a new unit U having holes in which tapers are to be cut is mountedin the carrier, such a new unit being assumed in Figure 15. The cycle ofoperations is thereupon repeated.

As will appear from the foregoing description in the operation of themachine the boring head and the work unit each have a cycle ofstep-by-step movements, these being coordinated and constituting aseries of operative steps in each of which the boring head and the workunit are in cooperative relation.

By way of recapitulation these steps are graphically illustrated inFigures 13 and 14 which are to be read together, Figure 13 illustratingthe cycle of movements of the boring head and Figure 14 illustrating thecycle of movements of the work unit. g

' xFigures'l-3 and 1.4 are to be considered in relation to thepreviousdescription of the-..-severa1- steps asqbasedtupon the disclosures of.Figures .15 through '20 land Figures '39 through 43. With the boringhead in position-F and. the work unit in vwhich tapers are to be cut in-position B (Figure 15) the first step S1 as shown by the graphof'Figure 14 is the-movement of the work unit from position'B toposition C (Figures 16 and 39). With the work unit in position C thesecond step S2 as shown by the graph'of Figur'e '13 is thecutterfeedingmovement of the boring head from position-F toposition G(Figures 16 and 39 and-17 and 40) in which thecutters 33 and 34 formtheztaper. of thewall of the anterior opening O.- With the boring headinposition Gthe third step S3 as show-n'by the graph of Figure 14 is themovement-ofthework unit formpositi'onCtoposition D-(Figures 17 and 40).With the --work unit in position D the fourth step S4 as shown bythegraph of Figure 131's the cutter feeding-movement of thc'boring headfrom position G'to position H (broken lines'Figure 17) in whichthecutters35 and '36 torm'the taper of the wall of the :posterioropening 0. .With the boring-head in position I-I the'fifth step S5 asshown by the graph of Figure, 14 is the movement of the ork unit fromposition D to position 'E (Figures 18 and 41). Withthe WOl'kjUIllt inposition E the sixth step S6 as shown by the graph of Figure 13 is theretractile movement of the boring headfrom position H to position I(Figures 19 and 42). With the boring head in position I the seventh stepS7 as shown by the graphof'Figure 14 is the movement of the work unitfrom position E to position 8 (Figures 20 and 43). With the work unit inposition B the eighth step S8 as shown by the graph of Figure 13 is themovement of the boring head from position I- to position F (Figure 15and broken lines of Figures and 43). At this stage the work unit inwhich tapershave been cut is removed and. a work unit in which tapersare to be cut is positioned and secured upon the carrier.

In respectto the foregoing description of the operative steps ofmovement of the parts it will be seen that the axis W of theshaft.5 andspindle 9 rotates about the major axis X of the journalso and 7 (Figure21) and as the spindle 9 is advanced in the operation of the machinethe'ax-is W generates opposed cones which have their apices at the pointZ. With the boring head and the work unitin theirinactive positions asshown in Figure 15 the horizontal axis -Y of the boring 'head is alinedor coincident with the axis X of the -journals-6 and 7 (Figure 22). Whenthe boring head is moved throughthe steps S2-and-S4 (Figures 16 and '18)its axis Y hooves away from the axis X but is maintained in parallelrelation to 'it. Thiswill be-apparent-from a comparison "of Figures 22'and 23. I From the foregoing description it will be apparent that thetaper in the anterior wall'isformed by the pair r of cutters-whieh havethe greater degree of projection from the "periphery-of the boring head;that when the taper-is to be out with itsmaximum diametersin extremerelation and its minimum-diameters in mean relation, the cutting ofthetaper' isproduced by the cutters which move radially toward the -axisX; and that when the taper-is to be cut with its minimum-diameters inextreme relation .and its'maximum diameters in-mean relation the cuttingof the taper is producedby the cutters which move away from the axis X.

Referring in detail to the cutting of the taper with itsrmaximumdiameters tin-extreme relation and its minimumdiameters=inmean relationas shown-in-Figures 15 through 20 and "39 through 43:

In the movement of the boringhead through the-step SZ-tlro-taperis cutin the wall of the interior opening 0 by the cutters-33 and 34"witlrits"maximum and minimum diameters rcspectivelyat the outer and inner facesof the anterior wall A. This is for the -reason-that :while the axis .3of the borinng head 'is being moved away from the axis X the cutters 33;and 34 are being, progressively moved radially nearer to the axis X,thereby c-utting spirals ofprogressively.diminishing diametersandproducing the tapering out which is best illustrated by theextension'lines of Figure 17. When the boringhead is moved through thestep S4 (Figure 17) its axis Y continues, in parallel relation, to moveaway from the .axis X. In the movement of the boring head through thestep S4 the taper is cut in the wall of the posterior opening 0 bythecutters 35 and 36, this taper having its minimum and maximumdiameters respectively .at the inner and outer faces of the posteriorwall P. This is for the reason that during the movement of the boringhead through the .step S4 the cutters 35 and 36 at the same time arebeing progressively moved radially further from the axis X, therebycutting spirals of progressively increasing diameters and producing thetapering out which is best illustrated by theextension linesof=Figure18.

The .piston stems 55, 66-and 81 are of similar construc-' tion, thedetails-being.,shown in Figure 24, asectional view of the inotor64. Thepiston stem consists of an inner tubular. part -88 and am enclosingoutertubular part 89, these parts being.connected-to the pistoneGSand tothe .supportinglug .68. The part 88 has an-axiahp'assage 90 whichextendsbetween its. endsand is .open to the cylinder space :at the front of thepiston, i. e. the cylinder spaceat the rightof the piston, :Figure 24being-considered'. v The part 8.8 .hasend portions 91 of greaterdiameter than its .body portion, .-these .being fitted in sealedrelation in thepart 89. The reduction in diameter of the body portion ofthe part-88 provides :a channel 92 of annular cross section.

Theliquid flow paths are the same for theseveral piston stems.Thepassages .90 of the pistonstems .66 and 81 are, connected in eachinstance externally of the cylinder to a liquidfiow tube 93. The passage90 of the piston stem is similarly. connected to. a corresponding-liquidflow tube 93. The operating liquidfiows in either direction throughthepassages and theconnected-liquid flow-tubes, the flow of the liquidinto-thewcylindcr space at either side of the piston effecting thecorresponding movement of the cylinder and the flow of theliquid fromthat space enabling the movement of the cylinder. in the oppositedirection. The channels 92of the piston stems 66'and'81 are connected ineachinstance externally of the cylinder to a liquid flow tube 94;Thezchannel 92 of the piston stem 55 is similarly connected: toacorresponding liquid flow. tube 94. The tchannel. :92 communicates withthe cylinder space behind the piston .through an opening 95 formed inthe part 89. adjacent the piston. The operating liquid flows ineitherdirectionthrough the channels 92 and the connected .liquidflowtubes into the cylinder space at either side .of the piston efiecting acorresponding movement of the cylinder andthe flow 0f the liquid fromthatspace enabling themovement of the cylinder in the oppositedirection.

The flow of. the liquid is effected by apump of any suitableconstruction, illustration of which -is deemed unnecessary. The controlof the :fiow.-of the-liquid is effected by valves, severally provided inoperative relation to the liquid flow tubes connected to eachpiston-stem.

The manual valve .63, as above pointed out,-controls the flow of theliquidtin relation to .thepiston-stcmSS. :The flow of the..liquid inrelation to :the piston stems 66xand 81 is controlled by-automaticallyoperated valves --96 and 96a respectively. Figure 11 shows .the valve96,the valve 96:? being similar inconstruction andoperation. The-valve 36includes avalvc casing97 and an enclosed valve body 93. The casing 97and valve-body 98 are preferably of cylindricalform, the va'lve bodyhaving a close fit -vithin thechamber of the-casing 97 andbeing slidablebetween its end walls.

The-valve casingis providedadjacent its-respectiveends with liquid inletnipples 99' and IOG-andbetWeen these with a liquid return nipple 101.The liquid-supply line s s-seas I (not shown) from the pump is connectedto liquid flow pipes (Figure 102 and 103 and the liquid return line (notshown) to the pump is connected to a liquid return pipe 104. The nipples99 of the valves 96 and 96a com municate with a supply branch 105(Figure 6) and the nipples 100 similarly communicate with a supplybranch 106. The liquidflow pipes 102 and 103 are connected respectivelyto the branches 105 and 106. The nipples 101 of the valves 96 and 96aare connected by a branch 107 to which the return. pipe 104 isconnected. Each valve casing 97 is also provided with nipples 108 and109 in angular relation to the nipples 99, 100, 101. The liquid flowtubes 93 and 94 are connected to the nipples 108 and 109 respectively.The valve body 93 is formed with circumferential channels 110 and 111.The valve casing 97 is formed with' a longitudinal passage 112 at alltimes in open communication at an intermediate point with the returnnipple 101, the passage 112 having terminal branches 11? and 114 whichare open to the inner face of the valve casing chamber. The valve casing97 is also formed with longitudinal passages115 and 116 whichrespectively are at alltimes in communication with the nipples 108 and109.- The passage 115 has terminal branches 117 and 118 and the passage116 has similar terminal branches 119 and .120, the several terminalbranches being open to the inner face of the valve casing chamber. i

The .valve body9 has oper ative left and right positions, Figure llbeing considered. The corresponding motor 64 is shown in Figure 24. Inits position at the right, as indicated by broken lines in Figure 11,the channel 110'registers with the nipple 100 and the branch 117,and'the channel 111 simultaneouslyregisters with the branches 114 and119, the valvebody closing the branches 113,113 and the nipple 109 andthe branch 120. In this position of the valve body the flow of liquid isthrough the nipple 100, the channel 110, the branch 117,the.nipple 108and the pipe 93 and the axial passage 90 ofthe piston stem 66 to thecylinder space in front of the piston 65 whereby pressure is applied tothe right end head of the cylinder 67 to move it to the right, FiguresSand 24 beingconsidered. At the same time, the movement of the cylinder67 to the right thereby being made possible, liquid flows from thecylinder space behind the piston 65 through the opening 95, the channel92, the tube 94, the nipple 109, the branch 119, the channel 111, thebranch 114, the passage 112, the nipple 101 and the return tube 104 tothe liquid return line which leads to the low pressure sideof the pump.In the position of the valve body 98 at the left as shown in full linesthe channel 111 registers with the nipple 99 and the branch 120 and thechannel 110 simultaneously register with the branches 113 and 118, thevalve body closing the branches 114 and 119, the nipple 100 and thebranch 117; In this position of the valve body the flow of liquid isthrough the nipple 99, the channel 111, the branch 120, the nipple 109,the tube 94, the channel 92 and the opening 95 to the cylinder spacebehind the piston 65 whereby pressure is applied to the left end head ofthe cylinder 67 to move it to the left. At the same time, the movementof the cylinder 67 to the left thereby being made possible, liquid flowsfrom the cylinder space in front of the piston as through the passage90, the tube 93, the nipple 108, the branch 115, the channel 110, thebranch 115, the passage 112, the nipple 101 and the return tube 104 tothe liquid return line which leads to the low pressure side of the pump.

The liquid flow circuits of the valve 96a and the associated motor 77are similar to those of the valve 96 and the associated motor 64.

In the case of the motor 77 the movements of the cylinder 79 to effectthe operations of the boring heads are to the right, Figure 5 beingconsidered, and the operating fluid for such movements is deliveredthrough the flow tube 93 and the passage 90 to the cylinder space in i 12 front of the piston 78. It is preferable that provision be made forregulating the rate of flow of the operating fiuiduand the flow tube 93therefore is provided with a shunt 121(Figure' 6) in which is fitted amanually adjust-able regulating valve 122. The tube 93 carries a checkvalve 123. between the points of connection of the shunt 121 whichpermits the free retrograde flow of the operating fluid throughthe tube93 but compels the how of the operating fluid through the shunt 121 in.connection with its delivery to the cylinder space in front of thepiston 78. The valve body 93, in addition to the extreme or left andright operative positions which establish the liquid flow circuits abovedescribed, has an intermediate or neutral position sufiicientlyindicated in Figure 11 by the showing of the channels and 111 in brokenlines coincident with transverse planes N. In this position the valvebody cuts off the communication with the channels 110 and 111 of thenipples 99, 100, 108 and 109 and the branches 113, 114, 117, 118,119 andand thereby functions as a barrier, rendering the liquid flow circuitsinoperative and causing the parts controlled by the particular fluidmotor 96 or 96a as the case may be, namely the work unit U and theboring heads10, to remain in the positions to which theyfwere moved inconsequence of the immediately preceding operative movement of the valvebody. The duration of the valve body in either of its operativepositions determines the extent of movement of thecontrolled parts, i.e. the work unit and the boring heads, and its duration in the neutralposition determines the periods of restof the controlled parts.Accordingly each valve body 98 is under the control of a suitablegoverning mechanism to be later'described. Thereby the periods ofmovements and rest of the controlled parts are coordinated, all asabovedescribed and sufficiently shown in the complementary graphs ofFigures 13 and 14.

The manually operated valve 63 for controlling the flow of the operatingliquid with respect to the work clamping means, that is to. say throughthe liquid flow tubes 93 and 9 1, may be of any suitable construction,the

details of one such construction being shown in Figures 25, 26 and 27.As shown in these figures the valve 63 is of the turning plug type andcomprises a casing 124 and an enclosedrctatably mounted valve body 125,one of the mounting trunnions of which carries an operating handle 126.The casing 124 is formed with upper and lower nipples 127 and 128preferablylocated in the central transverse plane and connected to therespective flow tubes 93 and 94'; At its opposite side the casing 124 isformed with nipples 129 and 130 preferably located at opposite sides ofthe central transverse plane. A liquid supply tube 131 leading from thehigh pressure side of the pump is connected to the nipple 129 and aliquid return tube 132 leading to the low pressure side of the pump isconnected to the nipple 130. The valve body 125 is formed with a passage133 which is preferably located in a central longitudinalplane and atone end, according to the position of the valve body, directlycommunicates with either of the nipples 127 or 128, its opposite endcommunicating at a central point with a peripheral recess 134 which alsoconstitutes a liquid flow passage and is at all times in communicationwith the nipple 129 to which the supply tube 131 is connected. Since thenipples 127 and 128 are in a centraltransverse plane of the valve casing124 and the nipple 129 is at: one-side of such plane the passage 133 islaterally inclined as shown in Figure 25. For return flow purposes thevalve body 125 is also formed with passages 135, 136 and 137, thesebeing radially directed and in mutual communication at a point along thecentral axis of the valve body. In one operative position of the valvebody as shown in Figure 27 the passage 135 (which extends to theperiphery of the valve body) communicates with the nipple 128 and thepassage 136 is in a neutral position as shown in broken lines at 136:;in Figure 26. In the second operative position of the valvebody thepassage 136 (which also ex-, tends to the periphery ofthe valve body)communicates with the nipple 1127' and the passage 135 is in a neutralposition as shown in broken lines at 135a. The passage l37-communicatesat a central point with a peripheral recess 138 which also constitutes aliquid flow passage and is at all times in communication with the nipple130 to which the return tube 132 is connected. Since the nipple 131i isat one side of the transverse plane in which the nipples 1'27 and 128'are located the passages 135, 136 and 137 are in a common planelaterally inclined as shown in Figure in a direction opposite to theinclination of the passage 133.

In Figure 3 it is assumed that the valve body is positioned for thedelivery of the operating fluid to the cylinder space below the piston54, this position being shown in Figures 26 and 27. With the valve bodyso positioned the operating liquid flows from the pipe 131 through therecess 134, the passage 1'33, nipple 127, tube 93' and passage into thecylinder space below the piston 54, thereby to move the cylinderdownward and effect the clamping action. This downward movement of thecylinder is permitted by the escape of the operating liquid from thecylinder space above the piston 54, the return flow of the liquid beingthrough the opening 95, the channel 92, the tube 94, the nipple 128, thepassages 1'35 and 137, the recess 138, the nipple and the return tube132 to the low pressure side of the pump.

Any suitable means may be provided for limiting the movement of thehandle 126 into either of the positions required by the vlave body 125.The positions of the valve handle 126 shown respectively in full linesand in broken lines 126a, Figures 2, 26 and 27 may be called clockwiseand counterclockwise.

When the cylinder 53 is to be moved to diseangage the clamping elementsand permit the removal of the work piece from its carrier the handle 126is moved to its counterclockwise position. Thereupon the passage 133 isbrought into communication with the nipple 128, the passage 136 isbrought into communication with the nipple 127 and the passage 135' isbrought into its neutral position 135a.

With the valve body so positioned the operating liquid flows from thepipe 131 through the recess 134, the passage 133, nipple 128, tube 94,channel 92 and opening 95 into the cylinder space above the piston 54,thereby to move the cylinder upward with the resultant release of thework unit. This upward movement of the cylinder is permitted by theescape of the operating liquid from the cylinder space below the piston,the return flow of the liquid being through the passage 90, tube 93,nipple 127, passages 136 and 137, passage 138, nipple 130'and returntube 132 to the low pressure side of the pump. When the elements 57 havebeen sufficiently disengaged consequent to the movement of the handle126'to its counterclockwise position the work unit U is removed from itscarrier 44.

The movementsof the valve bodies 98 of the valves 96 and 96a arepreferably effected by double acting solenoids 1'39 and 139arespectively (Figures 6 and 28). Since such solenoids are of well knownconstruction illustration of their details is not} required. It will besufficient to point out that each includes opposed windings 1 42 and 143and any usual means for normally holding their armatures 140 in acentral'position which is also a neutral position. The armature stems141 extend through openings in the adjacent heads of the correspondingvalve casings9-"l and are connected to the valve bodies. 7

When the boring heads and the work unit are in the relative positionsshown in Figure 15 the armatures of both solenoids are in neutralposition, these positions being assumed in Figures 6 and 28 In thesepositions the armatures hold the valve bodies 98 in their neutralpositions. The windings 142 and 143 are used toeffect themovem ent ofthe valve bodies 98 from their neutral 16 positions to their extremepositions at the left and right respectively (Figure 11 beingconsidered). I

The energization of the windings 142 and 143 of the two solenoids iscontrolled by a cyclically movable governing element which is preferablyin the form of a rotatable contact carrying disc 144 (Figures 6, 12 and28) mounted detachably but in driven relation on the shaft of anelectric motor 145, one complete revolution of the element 144corresponding to a complete cycle of operation of the machine asindicated by the complementary graphs of Figures 13 and 14.

The contact carrying disc 144 is composed of suitable insulatingmaterial and is shown in sufficient detail in Figure 12. On one of itsflat faces it is provided with contacts for carrying out the steps S1 toS8 illustrated in the graphs of Figures 13 and -14. The contacts are ofarcuate forrn and are indicated in their relation to the several stepsby the indexletter a, hence being designated as Sla, S211, S3a, S4a,S5a, S611, 87a, and 88a. The movable contacts Sl'a through 88a areseverally in cooperation with stationary contacts 146, 147, 148 and 149located at different distances radially from the. center of the disc 144and preferably arranged in a radial line. The contacts Sla, 83a and 85aengage the stationary contact 146. The contact S7a engages thestationary contact 147. The contacts S2a andS4a engage the stationarycontact 148, and the contacts 86a and 88a engagethe stationary contact149. Hence the contacts Sla through S8a-are variously arranged alongconcentric circles which correspond severally in radial location to theradial location of the cooperating stationary contacts.

' The graph ofFigure 14 shows the movements of the work unit, thesemovements being the steps S1, S3, S5 and S7. The advancing movements ofthe work unit are effected by the engagement of the movable contactsSla, 83a, $501 with the stationary contact 146 and the retractilemovement of the work unit is efiected by the engagement of the movablecontact S7a with the stationary contact 147; The annular extent of eachof the contacts Sla, 83a, 85a and 37a determines the period of theirengagement with the companion stationary contact and hence dictates theduration of the valve body in the corresponding position and therebydetermines the extent of movement of the work unit. When each of theseveral contacts Sla, S341, 85a and 87a has passed beyond, i. e.disengaged, the stationary contact with which it cooperates thesolenoi'd armature is returned by the solenoid mechanism to its neutralposition and the work unit remains in the position to which it has beenmoved for a period dictated by the spacing between the adjacent contactsof the annular series Sla, 33a, 55a and- 57a. In detail: The contactSlaeffects the movement of the work unit from the position of Figure 15 tothe position of Figures 16 and 39 (step S1), the valve body 98 of thevalve 96 "being moved. to its operative position at the left, Figure 11being-"considered, and when the cont-act Sla passes beyond thecorresponding stationary contact 146 the armature of the solenoid 139 isshifted back to its neutral position, thereby moving the valve body 98of the valve 96' back to its neutral position. The work unit remains inits position shown in Figures 16 and 39 for a period correspondingto thespacing of the contacts Sla and 83a and during this period the boringheads 10 are moved through the step S2 (Figure 13). Upon the completionof step S2 of the boring heads the movable contact 83a engages thestationary contact 146 with the result of the work unit being similarlymoved through step S3 (Figure 14) to the position shown in Figure 17.When the contact 83a passes beyond the contact 146 the armature oi thesolenoid 139 is again shifted back to its neutral position, therebymoving the valve body 98 ,of the valve 96 to its neutral position withthe result that the work unit remains in its position shown in Figures17 and 40 for a period corresponding to the spacing of the contacts 53aand 55a and during this period the boring heads 10 greases 17 are movedthrough step S4. Upon the completion of the step S4 of the boring headsthe movable contact 85 1 engages the stationary contact 146 with theresult of the work unit being similarly moved through the step S5 to theposition shown in Figures 18 and 41. When the contact 85a passes beyondthe contact 146 the armature of the solenoid 139 is again shifted backto its neutral position, thereby moving the valve body 98 of the valve96 to its neutral position with the result that the work unit remains inits position shown in Figures 18 and 41 for a period corresponding tothe spacing of the contacts 85a and S7a and during this period theboring heads 16 are moved through the step S6, their initial retractilestep which is from their positions shown in Figures 18 and 41 to theirpositions shown in Figures 19 and 42. Upon the completion of the step S6of the boring heads the movable contact S7a engages the stationarycontact 147, the valve body 98 of the valve 96 being then moved to itsoperative position at the right with the result that the work is movedthrough its retractile step to the position shown in Figure 20.Thereupon the boring heads are moved through the step S8, their finalretractile step, to their positions shown in broken lines in Figure 20.The contact 146 is connected by a wire 150 (Figure 28) to the winding142 of the solenoid 139 and the contact 147 is connected by a wire 151to the winding 143 of the solenoid 139. The energization of the winding142 of the solenoid 139 effects the advancing movements of the workunit, that is to say movements to the left through the steps S1, S3 andS5, Figure 5 being considered, and the energization of the winding 143of the solenoid 139 elfects the retractile movement of the work unit, amovement to the right through the step S7, all as above described. Theadvancing movements of the boring heads are .to the right,

Figure 5 being considered, and are effected. by the engagement of themovable contacts 82a and 84a with the stationary contact 148 and theretractile movements of the boring head are to the left and are effectedby the engagement of the movable contacts 86a and 58a with thestationary contact 149. The energization .of the winding 143 of thesolenoid 139a effects the movement of the valve body 98 of the valve 96ato the left (Figure 11 being considered) with resultant advancingmovements of the boring heads, that is to say movements to the right andthe energization of the winding 142 of the solenoid 139a effects themovements of the valve body 93 of the valve 96a to the left withresultantretractile movements of the boring heads. The contact 148 isconnected to the winding 143 of the solenoid 139a by a wire 152 and thecontact 149 is connected to the winding 142 of the solenoid 139a by awire 153. When the several contacts 82a, 84a, 86a and 88a pass beyondtheir corresponding stationary contacts the mechanism of the solenoid139a returns the armature to the neutral position with resultantmovement of the valve body 98 of the valve 96a to its neutral position,the boring heads thereupon remaining in the positions to which they werepreviously moved.

The contact carrying disc 144 is provided with a pcripheral contact 154.A current supply line 155 is connected at a neutral point to all of thewindings of both solenoids. A current return line 156 has a constantbrush contact with the peripheral contact 154 of the carrier 144. Themovable contacts Sla through 88a are also connected to the peripheralcontact 154 of the carrier144. The circuits for the .energization of thesolenoids may be traced as follows with reference to Figure 28: Whenanyof the movable contacts Sla, 83a and S511 arein engagemcnt with thecompanion stationary contact 146 the flow of current is from the supplyline 155 through the winding .142 of the solenoid 139, the wire 150, thecontact 146, the movable contact engaged with thecontact 146, theperipheral contact 154 and the returnline 156. When the movable contact57a is engaged with the com panion stationary contact 147 the flow ofcurrent is from the supply line 155 through the winding 143 of thesolenoid 139, the wire 151, the contact 147, the peripheral contact 154and the return line 156. When either of the movable contacts S20 andS411. is in engagement with the companion stationary contact 148 theflow of current is from the supply line 155 through the winding 143 ofthe solenoid 139a, the wire 152, the contact 148, the movable contactengaged with the contact 148, the peripheral contact 154 and the returnline 156. When either of the movable contacts S61: and 88a is engagedwith the companion stationary contact 149 the flow of current is fromthe supply line 155 through the winding 142 of the solenoid 139a, thewire 153, the contact 149, the movable contact engaged with the contact149, and the return line 156.

When the step 88a is completed the supply of current to the motor isautomatically cut 011. At this time the boring head is in the positionrelatively to the processed work unit which is shown in broken lines inFigure 20. It is at this stage that the processed work unit is removedand an unprocessed work unit substituted. Thereupon a manual switch isoperated to close a circuit for initiating the operation of the motor,the contact disc 144 thereafter establishing the motor operatingcircuit, the cycle being completed as previously described.

The operating circuit for the motor 145 includes a contact 157 ofcircular outline mounted on the disc 144 at the side opposite themovable contacts Sla through S80. The contact 157 does not extendthrough a complete circle but is formed to provide a gap 158 (Figure12). The contact 157 cooperates with spaced stationary contacts 159 and160. During the operation of the machine the contact 157 engages both ofthe stationary contacts as shown schematically in Figure 28. The motoroperating circuit includes a feed wire 161 branching from the line wireand connected to one pole. The other pole of the motor is connected by awire 162 to the stationary contact 159. The stationary contact isconnected by a wire 163 to the return line 156. With the machine inoperation the motor circuit may be traced as follows: Through the wire161, the motor, the wire 162, the stationary contact 159, the movablecontact 157, the stationary contact 160 and the wire 163 to the returnline.

In Figure 12 the direction of rotation of the contact carrier disc 144is assumed to be counterclockwise as indicated by the arrow and theposition of the disc is assumed to be that in which the motor operatingcircuit has been broken. The contact 159 is so located that when thestep S8 has been completed (the contact SSa at such time moving beyondthe contact 149) the con tact 157 will immediately thereupon move beyondthe stationary contact 159 which will then be in the gap 158 as shown inFigure 12. Thereby the operating circuit for the motor 155 is broken toenable the removal of "the processed work unit and the substitution ofan unprocessed unit. When this has been done the motor starting circuitis closed manually. This circuit includes a wire 164 connected to thesame pole of the motor as the wire 162 and extending to a stationarycontact 165 shown schematically in Figure 28 and which may be of anysuitable construction and a manually operated switch 166 held normallyopen, the other stationary switch contact 167 being connected by a wire168 to the return line 156. After the unprocessed work unit has beensecured in position in the manner previously described the switch 166 isoperated manually to close the motor starting circuit through thecontacts 165 and 167. This circuit is traced through the wire161, themotor, the wire 164, the stationary switch contact 165, the movablecontact of the switch, the stationary switch contact 167, and the returnwire 156. The closing of the manual switch 166 re sults in a movement ofthe contact carrier 144 in which the gap 158 passes beyond thestationary contact 159 at

